The present application claims foreign priority under 35 U.S.C. xc2xa7 119 of Swiss Application No. 1789/99 filed Sep. 28, 1999.
1. Field of the Invention
The invention relates to generally to microscopes, and more particularly to a stereomicroscope with an interface or a connecting device to which accessories can be attached.
2. Description of the Related Art
An established microscope, the xe2x80x9cM841,xe2x80x9d developed by Leica Microsystems AG of Heerbrugg, Switzerland, assignee of the present application, has two independent optical paths, each with its own zoom and with a shared main objective. The two optical paths are positioned at right angles, such that an assistant can directly watch a surgeon at work in the operating field. Given the independence of the two optical paths, there are no losses in light, so that both the surgeon and the assistant can view an optimally illuminated operating field. The M841 is frequently used in eye surgery. Here the assistant""s tube is positioned to the side of the main microscope body, and thus to the side of the patient""s head, on a bridge that projects outwards to a certain degree.
Depending on whether the right or the left eye is operated on, the assistant""s tube is required on the left or right side of the patient""s head, while the surgeon always sits in front of the patient""s head and positions his or her surgeon""s tube roughly in line with the head.
Reversing the position of the assistant""s tube from right to left normally occurs in this manner:
a) removal of the surgeon""s tube;
b) removal of the assistant""s bridge;
c) remounting of the assistant""s bridge, but swiveled 180xc2x0 around the optical axis of the main objective; and
d) remounting of the surgeon""s tube.
This change takes some time and requires skill. It is frequently the case, therefore, that technical assistants attempt to perform the change more simply and more quickly. They skip stage a) and attempt to remove the entire structure at once and perform the remounting according to steps b) and c). This xe2x80x9cquick changexe2x80x9d requires special skill and does not correspond to the procedure indicated by the manufacturer.
The literature, to be sure, discloses mechanisms that permit rotation of a tube device around an optical axis, but there it is performed for a different purpose and with different means. For example, German patent DE 3333471C2xe2x80x94like the prior and similar DE 1217099 Bxe2x80x94describes a design permitting simultaneous observation for a first and second observer, in which two stereomicroscopes are so positioned one relative to the other that both observers view the same operating field. Here the two primary axes are positioned inside each other by means of a beam splitting mirror and are directed at the operating field. This design permits the two microscopes to be rotated around the optical axis, without the need for justification; i.e., the operator can select his own preferred angular tube position relative to the patient and the assistant""s tube will follow it accordingly. Thus, positions on diametric sides of the patient can also be occupied.
The assembly there includes the surgeon""s tube with the first microscope, including the assembly with the beam-splitter, and a second, associated microscope for the assistant. The assembly with the beam splitter can be rotated around the main axis of the first microscope.
Problems with respect to the speed of any desired change in position do not arise with this structure; nor are there any significant mounting requirements, since the xe2x80x9cstructurexe2x80x9d (or xe2x80x9csubstructurexe2x80x9d) is basically secured in undetachable form to the first microscope and hangs below the microscope. On the other hand, this known assembly cannot be universally employed, since the two microscopes are permanently secured to each other.
Apart from the above, this known solution has a serious disadvantage: because there are two microscopes, the assembly is large and heavy. The design of the splitting mirror leads to a reduction in brightness, both for the surgeon and for the assistant, and this is a disadvantage. The heavy weight has a particularly negative effect if the microscope is mounted on a stand, as is usually the case in the operating room. Heavy weights result in heavy counterbalancing weights and in a high center of gravity for the microscope stand. A high center of gravity has a negative effect on the tipping behavior of the assembly and should be avoided whenever possible.
The invention is based on the task of solving the problem of repositioning and allowing the bridge and the assistant""s tube to be converted in a simpler and faster manner. The present invention solves this problem for the first time in a satisfactory way.
In a special embodiment of the invention, the disadvantages of using two microscopes, one for the surgeon and one for the assistant, are avoided due to two independent optical paths provided in one microscope.
In accordance with the present invention, an interface device is provided for connecting an accessory part, such as a bridge for linking an assistant""s viewing, to a main body of a microscope. The interface device is characterized by the fact that it is connected to the main body of the microscope and/or to the accessory part, by a locking screw that is by design difficult to remove. For example, the screw head can have a a special design, such that its manipulation requires a special tool, or a cover can be provided for the screw, or the screw can be made unusable, so that the interface device is lastingly secured to the main body of the microscope. Locking screws as understood in the invention are all structural elements which make possible the locking of two structural elements. Included among these, therefore, are elbow lever clamps and the like.
The interface device generally comprises upper and lower circular parts that can rotate relative to each other and that are attached to each other to form a pivot bearing. In its lower region, the lower part is designed as a mounting cone. The upper part is designed as a connection device for receiving a mounting cone and consequently includes locking projections and a locking screw which will preferably be hard to manipulate, or will have a cover, or will otherwise be difficult to access and operate.
Naturally the bridge, which is designed to receive the assistant""s tube, is equipped with a connection for the operator""s tube; here, as is known, it is possible to attach any desired modules to the connections on the bridge.
Screws as understood in the invention are all structural elements which make possible the locking of two structural elements. Included among these, therefore, are elbow lever clamps and the like.